#!/usr/bin/env bash

# homeserverdns - https://ulrich.earth/code/homeserverdns
#
# Copyright (C) 2018  Christian Ulrich
# 
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# 
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.


# This script is called by homeserverdns-daemon for updating A/AAAA records.
# These environment variables will be set by homeserverdns-daemon:
#
# PROTOCOL      protocol name (gandi|dyndns|httpnet)
# API_ADDRESS   address for API requests, required for dnydns protocol
# USER          user name for authentication at the API
# AUTH_KEY      authentication token for authentication at the API
# DOMAIN        fqdn for which A/AAAA records will be set 
# L2_DOMAIN     second-level domain for which A/AAAA records will be set
# RECORD_NAME   name of the record to be set
# IP4           new value of the A record (IP4 or IP6 will be set exclusively)
# IP6           new value of the AAAA record (IP4 or IP6 will be set exclusively)
# TTL           new TTL value for the A/AAAA records, required for gandi protocol


### gandi.net LiveDNS API
### () -> status_code
function update_gandi {
    local url="https://dns.api.gandi.net/api/v5/domains/${L2_DOMAIN}/records/${RECORD_NAME}"
    local ip=""
    if [ -n "${IP4}" ]; then
        url="${url}/A" 
        ip=$IP4
    elif [ -n "${IP6}" ]; then
        url="${url}/AAAA"
        ip=$IP6
    fi
    status=$(curl -o /dev/null -s -w "%{http_code}\n" \
                  -X PUT \
                  -H "Content-Type:application/json" \
                  -H "X-Api-Key:${AUTH_KEY}" \
                  -d "{\"rrset_ttl\":${TTL},\"rrset_values\":[\"${ip}\"]}" \
                  $url)
    echo "${status}"
}


# FIXME: untested
### http.net DNS API v1
### () -> status_code
function update_httpnet {
    local current_ip4=$(dig A +short $DOMAIN)
    local current_ip6=$(dig AAAA +short $DOMAIN)
    local url="https://partner.http.net/api/dns/v1/json/zoneUpdate"
    local items_add=""
    local items_delete=""
    if [ -n "${IP4}" ]; then
        items_add="{\"name\":\"${DOMAIN}\",\"type\":\"A\",\"content\":\"${IP4}\",\"ttl\":\"${TTL}\"}"
    elif [ -n "${IP6}" ]; then
        items_add="{\"name\":\"${DOMAIN}\",\"type\":\"AAAA\",\"content\":\"${IP6}\",\"ttl\":\"${TTL}\"}"
    fi
    if [ -n "${current_ip4}" ]; then
        items_delete="{\"name\":\"${DOMAIN}\",\"type\":\"A\",\"content\":\"${current_ip4}\"}"
    fi
    if [ -n "${current_ip6}" ]; then
        items_delete="{\"name\":\"${DOMAIN}\",\"type\":\"AAAA\",\"content\":\"${current_ip6}\"}"
    fi
    status=$(curl -o /dev/null -s -w "%{http_code}\n" \
                  -X PUT \
                  -d "{\"authToken\":\"${AUTH_KEY}\"," \
                     "\"zoneConfig\":{\"name\":\"${L2_DOMAIN}\"}," \
                     "\"recordsToAdd\":[${items_add}]," \
                     "\"recordsToDelete\":[${items_delete}]}" \
                  $url)
    echo "${status}"
}


# FIXME: untested
### dyndns API v2/v3 API
### () -> status_code
function update_dyndns {
    local hostname=${L2_DOMAIN}
    if [ "${RECORD_NAME}" != "@" ]; then
        local hostname=$DOMAIN
    fi
    local address=${IP4:-$IP6}
    local url="https://${USER}:${AUTH_KEY}@${API_ADDRESS}?hostname=${hostname}&myip=${address}"
    status=$(curl -o /dev/null -s -w "%{http_code}\n" $url)
    echo "${url} ${status}"
}


eval "update_${PROTOCOL}"